[FIR] Don't remove subsumed members from intersection overrides's overriddens

This fixes a bunch of missing overridden symbols in IR.
This is also required for fixing KT-59921 in the following commit
where we need to keep all overridden symbols of intersection overrides
so that we can enhance them properly.

#KT-57300 Fixed
#KT-57299 Fixed
#KT-59921
#KT-57300
#KT-62788
#KT-64271
#KT-64382

compiler/testData/codegen/box/jvm8/javaDefaults/kt40920_map.jvm_abi.txt

@@ -1,13 +0,0 @@
-MODULE main
-	CLASS MyMap.class
-		METHOD getOrDefault(Ljava/lang/String;Ljava/lang/String;)Ljava/lang/String;
-			Annotation: method.invisibleAnnotations
-				K1
-					@Lkotlin/SinceKotlin;( version: 1.1 )
-				K2
-					---
-			Annotation: method.invisibleAnnotations
-				K1
-					@Lkotlin/internal/PlatformDependent;
-				K2
-					---

compiler/testData/codegen/box/jvm8/javaDefaults/kt40920_map.kt

@@ -3,7 +3,6 @@
 // TARGET_BACKEND: JVM
 // WITH_STDLIB
 // FULL_JDK
-// JVM_ABI_K1_K2_DIFF: KT-62788
 
 // FILE: main.kt
 var result = ""